A snap switch marked 'CO/ALR' is suitable for use with which types of conductors?

• A. Aluminum conductors
• B. Copper conductor
• C. Copper-clad aluminum conductors
• D. All of the above

Answer: (D)

CO/ALR on a snap switch means it is designed to be connected to multiple conductor materials: copper, aluminum, and copper-clad aluminum. The device is specifically rated to handle aluminum wiring without compromising the connection, and copper-clad aluminum is considered compatible because it’s essentially an aluminum conductor with a copper surface. So the switch can be used with all three types, making “all of the above” the best choice. When using aluminum or copper-clad aluminum, follow proper terminal preparation and torque guidelines to ensure a secure, lasting connection.